1. Technical Field of the Invention
The present invention relates to integrated telecommunication systems and, more particularly, to a system and method for provisioning Intelligent Network (IN)-based Value-Added Services in an integrated telecommunications network which includes a packet-switched network (PSN) portion operable with Session Initiation Protocol.
2. Description of Related Art
Coupled with the phenomenal growth in popularity of the Internet, there has been a tremendous interest in using packet-switched network (PSN) infrastructures (e.g., those based on Internet Protocol (IP) addressing) as a replacement for, or as an adjunct to, the existing circuit-switched network (CSN) infrastructures used in today""s telephony. From the network operators"" perspective, the inherent traffic aggregation in packet-switched infrastructures allows for a reduction in the cost of transmission and the infrastructure cost per end-user. Ultimately, such cost reductions enable the network operators to pass on the concomitant cost savings to the end-users.
Some of the market drivers that impel the existing Voice-over-IP (VOIP) technology are: improvements in the quality of IP telephony; the Internet phenomenon; emergence of standards; cost-effective price-points for advanced services via media-rich call management, et cetera. One of the emerging standards in this area is the well-known Session Initiation Protocol (SIP), developed by the Internet Engineering Task Force (IETF) for multimedia communications over PSNs. Using SIP, devices such as personal computers can inter-operate seamlessly in a vast inter-network, sharing a mixture of audio, video, and data across all forms of PSNs which may interface with CSN portions.
As is well-known in the telecommunications industry, services and service provisioning are the raison d""xc3xaatre of a telecommunications network, including VoIP networks. Services are typically categorized into (i) xe2x80x9cbasic servicesxe2x80x9d (i.e., services which allow basic call processes such as call establishment and termination) or (ii) xe2x80x9cadvanced servicesxe2x80x9d which are also commonly referred to as Value-Added Services (VAS). Examples of advanced services include split charging, 800-services, credit card calls, call forwarding, hunt group, et cetera. It is also well-known that advanced services operate as factors for market differentiation and are crucial for network operators"" (or service providers"") success.
Value-Added Services in SIP-based VoIP networks are known as xe2x80x9cstandard telephony servicesxe2x80x9d whose architecture draws quite heavily on the Internet""s xe2x80x9cend-to-endxe2x80x9d paradigm and focuses on service creation. While service provisioning schemes based on SIP""s service architecture offer certain strengths (e.g., flexibility in role mapping for realizing services with end-to-end connectivity and having intelligence distributed to the xe2x80x9cedgesxe2x80x9d of the network), there exist several disadvantages and drawbacks. For instance, in SIP, service logic is provided to be co-located with the SIP-based IP telephony entities. Accordingly, in current implementations, SIP-based networks do not have the capability to effectively access remote service logic, e.g., Intelligent Network (IN)-based logic, that is already deployed in the market and geared to provide an array of customer-validated VAS. Moreover, if the IN-based service logic were to be used today in the context of SIP, SIP-based entities would need to support IN protocols (i.e., IN Application Protocol (INAP) over Signaling System 7 (SS7) or over IP) in order to remotely access the IN service node (e.g., Service Control Point or SCP) containing the service logic.
Those skilled in the art should readily appreciate that a significant part of the problem in providing remote service access capability to SIP-based entities stems from the fact that the two protocols, SIP and IN, follow different approaches and cannot be easily combined harmoniously. As is well-known, SIP is a lightweight, text-based protocol designed for Internet applications where space efficiency is of little concern. On the other hand, IN protocols are binary (i.e., coded in the Abstract Syntax Notation or ASN) and optimized for providing a large variety of VAS with parameters provided in rather complicated data structures. Using IN protocols to remotely access service logic in the context of SIP-based networks, accordingly, implies imposing additional functionality on IP telephony entities and introducing an extra category of xe2x80x9cheavyweightxe2x80x9d protocols in the network environment.
Based on the foregoing, it should be apparent that there has arisen an acute need for a service provisioning solution which advantageously provides remote service access capability within a SIP-based telecommunications network. The present invention provides such a solution.
In one aspect, the present invention is directed to a method of providing a Value-Added Service (VAS) in a telecommunications network operable with Session Initiation Protocol (SIP). The telecommunications network includes a SIPext SSP server, a trigger server, and a service node supporting VAS that is operable with Intelligent Network Application Protocol (INAP). Before processing a call (originating or terminating) between two users, which is effectuated by receiving a request message in the SIPext SSP server, the SIPext SSP server consults a user profile stored in the trigger server when a message for a user subscribed with a service provider arrives thereat. While processing the call, upon encountering an armed detection point for the subscribed service, a SIP register request is formulated by the SIPext SSP server based on the user profile obtained from the trigger server. The register request preferably includes at least one header field which contains information specifying an operation that the service node is to perform with respect to the VAS. The header field further includes call context data associated with the call initiated by the first user.
Subsequently, the register request is transmitted by the SIPext SSP server to the service node which launches the SLP based on the operation specified in the header field and the call context data associated therewith. The service node then formulates a SIP response message and transmits it to the SIPext SSP server, the response message including a header field and a return result obtained in response to the execution of the SLP by the service node. The SIPext SSP server executes an action responsive to the header field and the return result in the response message received from the service node, wherein the action corresponds to the provisioning of the VAS. In an exemplary embodiment, the return result comprises a destination routing number for a call forwarding service subscribed by the second user.
In another aspect, the present invention is directed to an integrated telecommunications network for providing a Value-Added Service (VAS). The integrated telecommunications network comprises a SIPext SSP server which includes a proxy server and a service switching part. In one exemplary embodiment, the proxy server and the service switching part are addressable by two separate Internet Protocol (IP) addresses. The proxy server is provided for receiving a call initiation message from a first user with respect to a second user. The service switching part is included for determining if the second user has a subscription for the VAS. A trigger server containing user profiles associated with the VAS is also included in the telecommunications network. Also, the service switching part is provided with the capability for formulating a register request based on user profile information for the second user retrieved from the trigger server, wherein the register request includes a header field containing an operation associated with the VAS. The telecommunications network further includes a service node which contains an Intelligent Network Application Protocol (INAP)-compliant Service Logic Program (SLP) associated with the VAS and a SIPext SSP interface server for receiving and interpreting the register request from the service switching part. Preferably, the service node executes the SLP based on the contents of the header field in the register request received from the service switching part.